In the past, in the case of molding a product using an injection molding machine, predicted values were determined by simulation, for example by a procedure such as shown in FIG. 8 of the accompanying drawings, and the actual injection of molten resin was done based on these predicted values.
First, when shape data, which is the mold shape and resin object shape is input to the shape data input section 101, this shape data 103 is divided into minute elements so as to be usable in numerical analysis methods such as the finite element method, the boundary element method, and the difference method, and stored in the shape data storage section 105.
Next, when the flow amount and temperature of the filling resin are input to the injection condition data input section 111, the flow amount and temperature data 113 are numerically processed and stored in the data storage section 115.
Additionally, when the above-noted shape data 103 and filling resin flow amount and temperature 113 are input to the mold internal behavior analysis section 121, analysis is performed of the behavior of the molten resin as it fills the mold, analysis of the pressure-maintenance process from completion of filling to gate sealing, and analysis of the cooling process within the mold after gate sealing are performed, and behavior data 123 for behavior of the molding resin within the mold during these analyzed processes is calculated. Of these, the behavior data 123 is stored in the behavior data storage section 125.
In the above-noted prior art, however, only the amount of flow and temperature 113 of the molding resin are input to the injection condition data input section 111, there being no input of the compressibility of the molten resin remaining at the barrel within the cylinder, so that the compressibility of the molten resin that fills this part is not considered in the analysis. Because there is a large amount of molten resin in the barrel, unless the compressibility is considered, there is a risk that the actual injection conditions will be different from the values predicted by the simulation, making it necessary to use an actual machine to perform numerous adjustment and corrections of the predicted values. Additionally, if the compressibility of the molten resin remaining in the barrel changes, it is necessary at that point to again perform adjustment of the predicted values.
Additionally, in the above-noted prior art, there is no input of data with regard to operational delays in such constituent elements of the injection molding machine as motors and screws. Thus, using the simulation method of the past it was difficult to perform an evaluation of the performance of a controller in an injection molding machine having response such that the flow of molten resin filling the mold approaches the target response pattern.